Speed boat



W. J. SNADECKI SPEED BOAT June 30, 1931.

Filed May 2l 1928 Patented `lune 30, 1931 UNITED "STATES PATENTJQFFIC] WILLIAM J. sNADEcxI, or wEsTovER, VIRGINIA, AssIGNoR or ONE-THIRD irol FEED' L. PIGEON AND ONE-THIRD To ROY W. PieEoN, BOTH or BOSTON, MAssAcrIUsET'rs SPEED BOATy y Application led May 21,

My invention relates to the construction ofboats and particularly to that class known as speed boats. An essential of such boats is that they must be of a form and so constructed, that rapid movement through the i water shall be" made with a minimum of resistance. Another essential is that such a boat may be turned at high speed Without capsizing or shipping water, and with a minimum of slippage.

My invention consists in the formation and arrangement of the planking, from the keel to the water 'line on either side, and also the shape of the boat to insure stability.

I have found that by planking the shell of such a boat to conform, from water line to the keel, to the surface of a cone, that the resistance to the forward movement of the boat is materially reduced, and that the stability of the boat is increased, when aV sharp turn is made at high speed, by converging the bulwarks from a relatively broad beam to the gunwale.

IYhile I retain a shape of the bottom conforming to the surface of a cone, I construct the shell with the planking overlapping, or as it is connnonlyJcalled lap straked, and the individual strakes from the waterline to the keel on either side, converge from the stern forward, and for two-thirds or more of their length the exposed edges of the lapped Y strakes, form straight lines radial with the apex of the cone to the surface of which the strakes conform through such distance.

In the accompanying specilication and the drawings forming a part thereof, I have described and illustrated a boat in which my invention is embodied.

In the drawings Fig. l shows a front elevation of such a boat.

Fig. 2 is a diagrammatic side elevation, the projected joints of the strakes above the waterline being omitted to emphasize the essential featurev of my invention.

Fig. 3 is a diagrammatic plan showing the outline of the boat at its greatest beam and the outline at the gunwale.

Fig` 4.- is a reversed diagrammatic plan to 1928. Serial'No.279,477.`

from the waterline WL to the keel 13, taper from the stern forward, and conform for the greater part of their lengths to the surface of a, cone whose axis is AB, twisting as they near the bow to merge into the stem post 14, in outline, wedge shaped truncated at their junction with the stem post. Throughout the portion of eachstrake that conforms to the surface of the cone, the overlapping edge of each strake is substantially radial withthe cone apex, which is approximately on the waterline in advance of the stem post, at a predetermined position. Forward of an arbitrary line 5-5, the strakes twist to join the stem 14', and the overlapping edges of each of such strakes, form inclined planes with the waterline at a relatively sharp angle. It thus results that at and below the waterline rearwardly from the line 5 5 to the stern, each strake forms a plane with overlapping diverging edge in a straight line to the stern, the strakes and their edges forming forward of this line, inclined planes which tends to entrain a film of air 'as the boat is driven forward, the inclined planes tending to reduce the displacement by their lifting action, the entrained air operating to an appreciable extent as a cushion between the strakes and the water, thus reducing the frictional action of the water on the bottom of the boat. Above the waterline the shell is formed with a relatively broad beam, diverging from bow to stern, narrowing in to the gunwale, the contour of the shell being generally oval in cross section from the stern to near the bow, the sides merging into the stem post. In this form of shell, not only is the stability of the boat increased, relative to the draft, but there is a further advantage which will now be explained.

As the boat is propelled at high speed, a sharp change of direction will cause the boat to heel to a relatively great angle to the normal, and in the usual form of boat this would cause danger of capsizing or shipping of lo( water, or if the sides were made of sufHcien-t height to obviate this tendency, vthe sailing area of the boat would be broadened due to the displacement of the boat in combination with the inertia as the boat turned. By converging the sides upwardly from the section through its greatest beam and parallel with the waterline, I am enabled to obtain a sailing surface, when a turn is made, that is relatively narrow and deep rather than broad and shallow, and at the same time provide against capsizing on a sharp change of direction. As the resistance to propulsion depends on the advancing surface of the boat at the waterline, the narrowed beam presented on the turn, not only offsets the depth due to the displacement, but such depth in connection with the overlapping strake edges, operates to reduce the slippage on the turn. rIhe depth of draft on the waterline, developed in a turn, and due to the displacement, is greatest in the portion of the boat just forward of the stern, with the result that the planking extending to the bow, inclines upwardly in such position of the boat, and the planes thus engaging the water, tends to lift the boat and reduce the draft, permitting a quick swivelling on the submerged portion. To partially protect the propeller, I prefer to form the stern of the boat laterally concaved and concentric with an axis coincident with the extended longitudinal median plane of the boat, and inclined to the water line toward the bow of the boat. As hereinbefore stated the exposed edges of corresponding strakes at and below the water line are radial with the apex of the cone to which the strakes conform, it follows that all sections of the bottom at and below the waterline and parallel thereto, are approximately isosceles triangles with concave bases formed by the intersecting contours of the stern, and the boat as it is propelled through the water forms a spreading wave, the lap edges uniformly diverging t0 the stern and tending to reduce the back wash in the vicinity of the propeller, thus increasing its efficiency.

Having thus described my invention, I claim:

1. In a boat shell formed with lap strakes and with contour of sides generally oval from keel to gunwale, strakes from the water line to the keel on either side, substantially parallel with the water line, and conforming for the major part of their length from the stern, to the surface of a cone with apex on the median line of the boat in advance of the bow and near the water line.

2. In a bloat shell formed with lap strakes and with a contour of sides generally oval from keel to gunwale, strakes from the water line to the keel on either side, substantially parallel with the water line, and conforming for the major part of their length from the stern, to the surface of a cone with apex on the median line of the boat in advance 0f the bow and near the water line, and whose exposed edges form strai ht lines, throughout such art of their lengti. 3. f n a boat shell formed with lap strakes and with a contour of sides generally oval from keel to gunwale, strakes from the water line to the keel on either side, substantially arallel with the water line, and conforming or the major part of their length from the stern, to the surface of a cone with apex on the median line of the boatin advance of the bow and near the water line, and whose exposed edges in such part of their length, are radial with the apex of the cone.

4. A boat shell in which the planking from the water line to the keel oneither side, is formed from a plurality of wedge shaped strakes, truncated at their respective junctions with .the stem post.

5. A boat shell in which the sides diverge from bow to stern, and curve inwardly from a maximum beam above the water line to the gunwale, the contour of the shell at any cross section taken normal to the water line; from stern to near the bow, being substantially an oval, truncated at the gunwales.

WILLIAM J. SNADECKI. 

